1 //===--------------------- PredicateExpander.cpp --------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 /// \file
9 /// Functionalities used by the Tablegen backends to expand machine predicates.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "PredicateExpander.h"
14 #include "CodeGenSchedule.h" // Definition of STIPredicateFunction.
15 
16 namespace llvm {
17 
18 void PredicateExpander::expandTrue(raw_ostream &OS) { OS << "true"; }
19 void PredicateExpander::expandFalse(raw_ostream &OS) { OS << "false"; }
20 
21 void PredicateExpander::expandCheckImmOperand(raw_ostream &OS, int OpIndex,
22                                               int ImmVal,
23                                               StringRef FunctionMapper) {
24   if (!FunctionMapper.empty())
25     OS << FunctionMapper << "(";
26   OS << "MI" << (isByRef() ? "." : "->") << "getOperand(" << OpIndex
27      << ").getImm()";
28   if (!FunctionMapper.empty())
29     OS << ")";
30   OS << (shouldNegate() ? " != " : " == ") << ImmVal;
31 }
32 
33 void PredicateExpander::expandCheckImmOperand(raw_ostream &OS, int OpIndex,
34                                               StringRef ImmVal,
35                                               StringRef FunctionMapper) {
36   if (ImmVal.empty())
37     expandCheckImmOperandSimple(OS, OpIndex, FunctionMapper);
38 
39   if (!FunctionMapper.empty())
40     OS << FunctionMapper << "(";
41   OS << "MI" << (isByRef() ? "." : "->") << "getOperand(" << OpIndex
42      << ").getImm()";
43   if (!FunctionMapper.empty())
44     OS << ")";
45   OS << (shouldNegate() ? " != " : " == ") << ImmVal;
46 }
47 
48 void PredicateExpander::expandCheckImmOperandSimple(raw_ostream &OS,
49                                                     int OpIndex,
50                                                     StringRef FunctionMapper) {
51   if (shouldNegate())
52     OS << "!";
53   if (!FunctionMapper.empty())
54     OS << FunctionMapper << "(";
55   OS << "MI" << (isByRef() ? "." : "->") << "getOperand(" << OpIndex
56      << ").getImm()";
57   if (!FunctionMapper.empty())
58     OS << ")";
59 }
60 
61 void PredicateExpander::expandCheckRegOperand(raw_ostream &OS, int OpIndex,
62                                               const Record *Reg,
63                                               StringRef FunctionMapper) {
64   assert(Reg->isSubClassOf("Register") && "Expected a register Record!");
65 
66   if (!FunctionMapper.empty())
67     OS << FunctionMapper << "(";
68   OS << "MI" << (isByRef() ? "." : "->") << "getOperand(" << OpIndex
69      << ").getReg()";
70   if (!FunctionMapper.empty())
71     OS << ")";
72   OS << (shouldNegate() ? " != " : " == ");
73   const StringRef Str = Reg->getValueAsString("Namespace");
74   if (!Str.empty())
75     OS << Str << "::";
76   OS << Reg->getName();
77 }
78 
79 
80 void PredicateExpander::expandCheckRegOperandSimple(raw_ostream &OS,
81                                                     int OpIndex,
82                                                     StringRef FunctionMapper) {
83   if (shouldNegate())
84     OS << "!";
85   if (!FunctionMapper.empty())
86     OS << FunctionMapper << "(";
87   OS << "MI" << (isByRef() ? "." : "->") << "getOperand(" << OpIndex
88      << ").getReg()";
89   if (!FunctionMapper.empty())
90     OS << ")";
91 }
92 
93 void PredicateExpander::expandCheckInvalidRegOperand(raw_ostream &OS,
94                                                      int OpIndex) {
95   OS << "MI" << (isByRef() ? "." : "->") << "getOperand(" << OpIndex
96      << ").getReg() " << (shouldNegate() ? "!= " : "== ") << "0";
97 }
98 
99 void PredicateExpander::expandCheckSameRegOperand(raw_ostream &OS, int First,
100                                                   int Second) {
101   OS << "MI" << (isByRef() ? "." : "->") << "getOperand(" << First
102      << ").getReg() " << (shouldNegate() ? "!=" : "==") << " MI"
103      << (isByRef() ? "." : "->") << "getOperand(" << Second << ").getReg()";
104 }
105 
106 void PredicateExpander::expandCheckNumOperands(raw_ostream &OS, int NumOps) {
107   OS << "MI" << (isByRef() ? "." : "->") << "getNumOperands() "
108      << (shouldNegate() ? "!= " : "== ") << NumOps;
109 }
110 
111 void PredicateExpander::expandCheckOpcode(raw_ostream &OS, const Record *Inst) {
112   OS << "MI" << (isByRef() ? "." : "->") << "getOpcode() "
113      << (shouldNegate() ? "!= " : "== ") << Inst->getValueAsString("Namespace")
114      << "::" << Inst->getName();
115 }
116 
117 void PredicateExpander::expandCheckOpcode(raw_ostream &OS,
118                                           const RecVec &Opcodes) {
119   assert(!Opcodes.empty() && "Expected at least one opcode to check!");
120   bool First = true;
121 
122   if (Opcodes.size() == 1) {
123     OS << "( ";
124     expandCheckOpcode(OS, Opcodes[0]);
125     OS << " )";
126     return;
127   }
128 
129   OS << '(';
130   increaseIndentLevel();
131   for (const Record *Rec : Opcodes) {
132     OS << '\n';
133     OS.indent(getIndentLevel() * 2);
134     if (!First)
135       OS << (shouldNegate() ? "&& " : "|| ");
136 
137     expandCheckOpcode(OS, Rec);
138     First = false;
139   }
140 
141   OS << '\n';
142   decreaseIndentLevel();
143   OS.indent(getIndentLevel() * 2);
144   OS << ')';
145 }
146 
147 void PredicateExpander::expandCheckPseudo(raw_ostream &OS,
148                                           const RecVec &Opcodes) {
149   if (shouldExpandForMC())
150     expandFalse(OS);
151   else
152     expandCheckOpcode(OS, Opcodes);
153 }
154 
155 void PredicateExpander::expandPredicateSequence(raw_ostream &OS,
156                                                 const RecVec &Sequence,
157                                                 bool IsCheckAll) {
158   assert(!Sequence.empty() && "Found an invalid empty predicate set!");
159   if (Sequence.size() == 1)
160     return expandPredicate(OS, Sequence[0]);
161 
162   // Okay, there is more than one predicate in the set.
163   bool First = true;
164   OS << (shouldNegate() ? "!(" : "(");
165   increaseIndentLevel();
166 
167   bool OldValue = shouldNegate();
168   setNegatePredicate(false);
169   for (const Record *Rec : Sequence) {
170     OS << '\n';
171     OS.indent(getIndentLevel() * 2);
172     if (!First)
173       OS << (IsCheckAll ? "&& " : "|| ");
174     expandPredicate(OS, Rec);
175     First = false;
176   }
177   OS << '\n';
178   decreaseIndentLevel();
179   OS.indent(getIndentLevel() * 2);
180   OS << ')';
181   setNegatePredicate(OldValue);
182 }
183 
184 void PredicateExpander::expandTIIFunctionCall(raw_ostream &OS,
185                                               StringRef MethodName) {
186   OS << (shouldNegate() ? "!" : "");
187   OS << TargetName << (shouldExpandForMC() ? "_MC::" : "InstrInfo::");
188   OS << MethodName << (isByRef() ? "(MI)" : "(*MI)");
189 }
190 
191 void PredicateExpander::expandCheckIsRegOperand(raw_ostream &OS, int OpIndex) {
192   OS << (shouldNegate() ? "!" : "") << "MI" << (isByRef() ? "." : "->")
193      << "getOperand(" << OpIndex << ").isReg() ";
194 }
195 
196 void PredicateExpander::expandCheckIsImmOperand(raw_ostream &OS, int OpIndex) {
197   OS << (shouldNegate() ? "!" : "") << "MI" << (isByRef() ? "." : "->")
198      << "getOperand(" << OpIndex << ").isImm() ";
199 }
200 
201 void PredicateExpander::expandCheckFunctionPredicate(raw_ostream &OS,
202                                                      StringRef MCInstFn,
203                                                      StringRef MachineInstrFn) {
204   OS << (shouldExpandForMC() ? MCInstFn : MachineInstrFn)
205      << (isByRef() ? "(MI)" : "(*MI)");
206 }
207 
208 void PredicateExpander::expandCheckNonPortable(raw_ostream &OS,
209                                                StringRef Code) {
210   if (shouldExpandForMC())
211     return expandFalse(OS);
212 
213   OS << '(' << Code << ')';
214 }
215 
216 void PredicateExpander::expandReturnStatement(raw_ostream &OS,
217                                               const Record *Rec) {
218   std::string Buffer;
219   raw_string_ostream SS(Buffer);
220 
221   SS << "return ";
222   expandPredicate(SS, Rec);
223   SS << ";";
224   SS.flush();
225   OS << Buffer;
226 }
227 
228 void PredicateExpander::expandOpcodeSwitchCase(raw_ostream &OS,
229                                                const Record *Rec) {
230   const RecVec &Opcodes = Rec->getValueAsListOfDefs("Opcodes");
231   for (const Record *Opcode : Opcodes) {
232     OS.indent(getIndentLevel() * 2);
233     OS << "case " << Opcode->getValueAsString("Namespace")
234        << "::" << Opcode->getName() << ":\n";
235   }
236 
237   increaseIndentLevel();
238   OS.indent(getIndentLevel() * 2);
239   expandStatement(OS, Rec->getValueAsDef("CaseStmt"));
240   decreaseIndentLevel();
241 }
242 
243 void PredicateExpander::expandOpcodeSwitchStatement(raw_ostream &OS,
244                                                     const RecVec &Cases,
245                                                     const Record *Default) {
246   std::string Buffer;
247   raw_string_ostream SS(Buffer);
248 
249   SS << "switch(MI" << (isByRef() ? "." : "->") << "getOpcode()) {\n";
250   for (const Record *Rec : Cases) {
251     expandOpcodeSwitchCase(SS, Rec);
252     SS << '\n';
253   }
254 
255   // Expand the default case.
256   SS.indent(getIndentLevel() * 2);
257   SS << "default:\n";
258 
259   increaseIndentLevel();
260   SS.indent(getIndentLevel() * 2);
261   expandStatement(SS, Default);
262   decreaseIndentLevel();
263   SS << '\n';
264 
265   SS.indent(getIndentLevel() * 2);
266   SS << "} // end of switch-stmt";
267   SS.flush();
268   OS << Buffer;
269 }
270 
271 void PredicateExpander::expandStatement(raw_ostream &OS, const Record *Rec) {
272   // Assume that padding has been added by the caller.
273   if (Rec->isSubClassOf("MCOpcodeSwitchStatement")) {
274     expandOpcodeSwitchStatement(OS, Rec->getValueAsListOfDefs("Cases"),
275                                 Rec->getValueAsDef("DefaultCase"));
276     return;
277   }
278 
279   if (Rec->isSubClassOf("MCReturnStatement")) {
280     expandReturnStatement(OS, Rec->getValueAsDef("Pred"));
281     return;
282   }
283 
284   llvm_unreachable("No known rules to expand this MCStatement");
285 }
286 
287 void PredicateExpander::expandPredicate(raw_ostream &OS, const Record *Rec) {
288   // Assume that padding has been added by the caller.
289   if (Rec->isSubClassOf("MCTrue")) {
290     if (shouldNegate())
291       return expandFalse(OS);
292     return expandTrue(OS);
293   }
294 
295   if (Rec->isSubClassOf("MCFalse")) {
296     if (shouldNegate())
297       return expandTrue(OS);
298     return expandFalse(OS);
299   }
300 
301   if (Rec->isSubClassOf("CheckNot")) {
302     flipNegatePredicate();
303     expandPredicate(OS, Rec->getValueAsDef("Pred"));
304     flipNegatePredicate();
305     return;
306   }
307 
308   if (Rec->isSubClassOf("CheckIsRegOperand"))
309     return expandCheckIsRegOperand(OS, Rec->getValueAsInt("OpIndex"));
310 
311   if (Rec->isSubClassOf("CheckIsImmOperand"))
312     return expandCheckIsImmOperand(OS, Rec->getValueAsInt("OpIndex"));
313 
314   if (Rec->isSubClassOf("CheckRegOperand"))
315     return expandCheckRegOperand(OS, Rec->getValueAsInt("OpIndex"),
316                                  Rec->getValueAsDef("Reg"),
317                                  Rec->getValueAsString("FunctionMapper"));
318 
319   if (Rec->isSubClassOf("CheckRegOperandSimple"))
320     return expandCheckRegOperandSimple(OS, Rec->getValueAsInt("OpIndex"),
321                                        Rec->getValueAsString("FunctionMapper"));
322 
323   if (Rec->isSubClassOf("CheckInvalidRegOperand"))
324     return expandCheckInvalidRegOperand(OS, Rec->getValueAsInt("OpIndex"));
325 
326   if (Rec->isSubClassOf("CheckImmOperand"))
327     return expandCheckImmOperand(OS, Rec->getValueAsInt("OpIndex"),
328                                  Rec->getValueAsInt("ImmVal"),
329                                  Rec->getValueAsString("FunctionMapper"));
330 
331   if (Rec->isSubClassOf("CheckImmOperand_s"))
332     return expandCheckImmOperand(OS, Rec->getValueAsInt("OpIndex"),
333                                  Rec->getValueAsString("ImmVal"),
334                                  Rec->getValueAsString("FunctionMapper"));
335 
336   if (Rec->isSubClassOf("CheckImmOperandSimple"))
337     return expandCheckImmOperandSimple(OS, Rec->getValueAsInt("OpIndex"),
338                                        Rec->getValueAsString("FunctionMapper"));
339 
340   if (Rec->isSubClassOf("CheckSameRegOperand"))
341     return expandCheckSameRegOperand(OS, Rec->getValueAsInt("FirstIndex"),
342                                      Rec->getValueAsInt("SecondIndex"));
343 
344   if (Rec->isSubClassOf("CheckNumOperands"))
345     return expandCheckNumOperands(OS, Rec->getValueAsInt("NumOps"));
346 
347   if (Rec->isSubClassOf("CheckPseudo"))
348     return expandCheckPseudo(OS, Rec->getValueAsListOfDefs("ValidOpcodes"));
349 
350   if (Rec->isSubClassOf("CheckOpcode"))
351     return expandCheckOpcode(OS, Rec->getValueAsListOfDefs("ValidOpcodes"));
352 
353   if (Rec->isSubClassOf("CheckAll"))
354     return expandPredicateSequence(OS, Rec->getValueAsListOfDefs("Predicates"),
355                                    /* AllOf */ true);
356 
357   if (Rec->isSubClassOf("CheckAny"))
358     return expandPredicateSequence(OS, Rec->getValueAsListOfDefs("Predicates"),
359                                    /* AllOf */ false);
360 
361   if (Rec->isSubClassOf("CheckFunctionPredicate"))
362     return expandCheckFunctionPredicate(
363         OS, Rec->getValueAsString("MCInstFnName"),
364         Rec->getValueAsString("MachineInstrFnName"));
365 
366   if (Rec->isSubClassOf("CheckNonPortable"))
367     return expandCheckNonPortable(OS, Rec->getValueAsString("CodeBlock"));
368 
369   if (Rec->isSubClassOf("TIIPredicate"))
370     return expandTIIFunctionCall(OS, Rec->getValueAsString("FunctionName"));
371 
372   llvm_unreachable("No known rules to expand this MCInstPredicate");
373 }
374 
375 void STIPredicateExpander::expandHeader(raw_ostream &OS,
376                                         const STIPredicateFunction &Fn) {
377   const Record *Rec = Fn.getDeclaration();
378   StringRef FunctionName = Rec->getValueAsString("Name");
379 
380   OS.indent(getIndentLevel() * 2);
381   OS << "bool ";
382   if (shouldExpandDefinition())
383     OS << getClassPrefix() << "::";
384   OS << FunctionName << "(";
385   if (shouldExpandForMC())
386     OS << "const MCInst " << (isByRef() ? "&" : "*") << "MI";
387   else
388     OS << "const MachineInstr " << (isByRef() ? "&" : "*") << "MI";
389   if (Rec->getValueAsBit("UpdatesOpcodeMask"))
390     OS << ", APInt &Mask";
391   OS << (shouldExpandForMC() ? ", unsigned ProcessorID) const " : ") const ");
392   if (shouldExpandDefinition()) {
393     OS << "{\n";
394     return;
395   }
396 
397   if (Rec->getValueAsBit("OverridesBaseClassMember"))
398     OS << "override";
399   OS << ";\n";
400 }
401 
402 void STIPredicateExpander::expandPrologue(raw_ostream &OS,
403                                           const STIPredicateFunction &Fn) {
404   RecVec Delegates = Fn.getDeclaration()->getValueAsListOfDefs("Delegates");
405   bool UpdatesOpcodeMask =
406       Fn.getDeclaration()->getValueAsBit("UpdatesOpcodeMask");
407 
408   increaseIndentLevel();
409   unsigned IndentLevel = getIndentLevel();
410   for (const Record *Delegate : Delegates) {
411     OS.indent(IndentLevel * 2);
412     OS << "if (" << Delegate->getValueAsString("Name") << "(MI";
413     if (UpdatesOpcodeMask)
414       OS << ", Mask";
415     if (shouldExpandForMC())
416       OS << ", ProcessorID";
417     OS << "))\n";
418     OS.indent((1 + IndentLevel) * 2);
419     OS << "return true;\n\n";
420   }
421 
422   if (shouldExpandForMC())
423     return;
424 
425   OS.indent(IndentLevel * 2);
426   OS << "unsigned ProcessorID = getSchedModel().getProcessorID();\n";
427 }
428 
429 void STIPredicateExpander::expandOpcodeGroup(raw_ostream &OS, const OpcodeGroup &Group,
430                                              bool ShouldUpdateOpcodeMask) {
431   const OpcodeInfo &OI = Group.getOpcodeInfo();
432   for (const PredicateInfo &PI : OI.getPredicates()) {
433     const APInt &ProcModelMask = PI.ProcModelMask;
434     bool FirstProcID = true;
435     for (unsigned I = 0, E = ProcModelMask.getActiveBits(); I < E; ++I) {
436       if (!ProcModelMask[I])
437         continue;
438 
439       if (FirstProcID) {
440         OS.indent(getIndentLevel() * 2);
441         OS << "if (ProcessorID == " << I;
442       } else {
443         OS << " || ProcessorID == " << I;
444       }
445       FirstProcID = false;
446     }
447 
448     OS << ") {\n";
449 
450     increaseIndentLevel();
451     OS.indent(getIndentLevel() * 2);
452     if (ShouldUpdateOpcodeMask) {
453       if (PI.OperandMask.isNullValue())
454         OS << "Mask.clearAllBits();\n";
455       else
456         OS << "Mask = " << PI.OperandMask << ";\n";
457       OS.indent(getIndentLevel() * 2);
458     }
459     OS << "return ";
460     expandPredicate(OS, PI.Predicate);
461     OS << ";\n";
462     decreaseIndentLevel();
463     OS.indent(getIndentLevel() * 2);
464     OS << "}\n";
465   }
466 }
467 
468 void STIPredicateExpander::expandBody(raw_ostream &OS,
469                                       const STIPredicateFunction &Fn) {
470   bool UpdatesOpcodeMask =
471       Fn.getDeclaration()->getValueAsBit("UpdatesOpcodeMask");
472 
473   unsigned IndentLevel = getIndentLevel();
474   OS.indent(IndentLevel * 2);
475   OS << "switch(MI" << (isByRef() ? "." : "->") << "getOpcode()) {\n";
476   OS.indent(IndentLevel * 2);
477   OS << "default:\n";
478   OS.indent(IndentLevel * 2);
479   OS << "  break;";
480 
481   for (const OpcodeGroup &Group : Fn.getGroups()) {
482     for (const Record *Opcode : Group.getOpcodes()) {
483       OS << '\n';
484       OS.indent(IndentLevel * 2);
485       OS << "case " << getTargetName() << "::" << Opcode->getName() << ":";
486     }
487 
488     OS << '\n';
489     increaseIndentLevel();
490     expandOpcodeGroup(OS, Group, UpdatesOpcodeMask);
491 
492     OS.indent(getIndentLevel() * 2);
493     OS << "break;\n";
494     decreaseIndentLevel();
495   }
496 
497   OS.indent(IndentLevel * 2);
498   OS << "}\n";
499 }
500 
501 void STIPredicateExpander::expandEpilogue(raw_ostream &OS,
502                                           const STIPredicateFunction &Fn) {
503   OS << '\n';
504   OS.indent(getIndentLevel() * 2);
505   OS << "return ";
506   expandPredicate(OS, Fn.getDefaultReturnPredicate());
507   OS << ";\n";
508 
509   decreaseIndentLevel();
510   OS.indent(getIndentLevel() * 2);
511   StringRef FunctionName = Fn.getDeclaration()->getValueAsString("Name");
512   OS << "} // " << ClassPrefix << "::" << FunctionName << "\n\n";
513 }
514 
515 void STIPredicateExpander::expandSTIPredicate(raw_ostream &OS,
516                                               const STIPredicateFunction &Fn) {
517   const Record *Rec = Fn.getDeclaration();
518   if (shouldExpandForMC() && !Rec->getValueAsBit("ExpandForMC"))
519     return;
520 
521   expandHeader(OS, Fn);
522   if (shouldExpandDefinition()) {
523     expandPrologue(OS, Fn);
524     expandBody(OS, Fn);
525     expandEpilogue(OS, Fn);
526   }
527 }
528 
529 } // namespace llvm
530